Treesearch

Sap and maple syrup equivalent production increased after a coniferous understory was removed from a sugarbush in northwestern Vermont. These increases, which became apparent the sixth year after treatment, were 14 and 17 percent for sap and syrup respectively, relative to the yields from an adjacent open sugarbush. The open sugarbush yields were used as the control in the analysis, to indicate the influence of weather conditions in each sapflow season. Understory removal also stimulated growth of the overstory maple trees.

A 2-year study of stem deformity in black cherry on the Allegheny and Monongahela National Forests revealed that insects, disease, frost, and browsing by deer were the major sources of injury to the terminal shoots of seedlings and saplings. Twenty-seven species of insects from 19 families and 5 orders were associated with young black cherry trees. Of these species, Archips sp., and Cecidomyia serotinae O.S., caused the most stem deformity. The percentage of trees damaged by these two species of insects ranged from 0 to 43 on six study areas during 1976-77. Damage from black knot disease,...

Red maple (Acer rubrum L.) seedlings were grown in a greenhouse using three treatments: two soil horizons, two soil moisture regimes, and three nutrient levels. Fertilization increased growth under moist conditions on the more fertile topsoil. Under dry conditions, fertilization had no effect on growth in subsoil, and slightly increased growth in topsoil. Without fertilization, growth was greater in the moist topsoil. Growth was most balanced when available soil N was 25 ppm, P was 25 to 75 ppm, and K was 75 to 100 ppm. Multiple regression equations relating growth to foliar nutrients were...

In tests of gross perception of Serpentine end matched (Sem) joints in oak and cherry display panels, there were no significant differences between the number of times the non-Sem panels were chosen and the number of these selections that could be attributed to chance. Results of separate tests of sensitivity of perception of Sem joints showed that the most conspicuous joints in oak and cherry panels were chosen most often, and that the least conspicuous joints were detected least often. Given proper selection of pieces to be end matched, and moderate finishing, Sem joints are difficult to...

Provides a practical method for rating the potential hazard of impending gypsy moth attacks to forest stands. Stepwise multiple regression analysis is used to develop equations for estimating tree mortality from easy-to-measure key characteristics of stand condition.

A study of the seeds and fruits of sugar maples from 32 provenances has shown that: (1) dry weight of seed and percentage of filled fruit varied genetically among and within provenances; (2) dry weight of seed and latitude of provenance are positively correlated; provenances from higher latitudes and colder temperatures exhibited higher weights; (3) the percentage of filled fruit was not significantly related to dry weight of seed and was negatively correlated with latitude; (4) dry weight of seed exhibited a complex pattern of genetic variation; in the northeast the variation was ecotypic...

Crop trees were released in an Appalachian hardwood stand (site index 70 for northern red oak) that had been clearcut 9 years earlier. We released 134 yellow-poplar, red oak, black cherry, and sugar maple stems of seedling origin to a 5-foot radius around the bole of each study tree; 140 comparable stems were not released. These trees were dominant, codominant, or intermediate, and all treated trees were released to a dominant crown position. On the basis of results 5 years after treatment, we do not recommend releasing crop trees of seedling origin for the species, site, and methods used...

Black cherry trees 4 to 6 inches in diameter at breast height (dbh) with live crown ratios ranging from 73 to 92 percent were pruned to 25, 50, or 75 percent of tree height or were left unpruned. Most trees can be pruned to 50 percent of tree height in one operation. Trees that have large crowns and that are frilly exposed on the southwest side should be pruned less severely. Pruning to 75 percent of tree height caused excessive epicormic branching, poor diameter growth, and serious cambium necrosis.

Positive correlations were established between morphological characteristics in eastern white pine seedlings and subsequent tolerance or sensitivity to air pollution 5 and 7 years after outplanting in Ohio plantations. Of 11 seedling variables, needle mottling was an accurate indicator of sensitivity or tolerance to air pollution. This characteristic, which may be genetically controlled, should allow for the detection and removal of sensitive white pines in the nursery during grading.

An econometric model of the domestic insulation board industry was developed to identify and quantify the major factors affecting quantity consumed and price. The factors identified were housing starts, residential improvement activity, disposable personal income, productivity, pulpwood and residue prices, and power costs. Disposable personal income was the most important of these factors, affecting both quantity and price. Annual projections of quantity and price show quantity increasing by 30 percent and price by 106 percent by the year 1990.